WNW&B - News

John P. King, Esquire
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215.569.0900
kingj@wnwlaw.com

Improving Philadelphia’s Standard of Care to Prevent Harm to Babies Born with Blood Platelet Disorders

From The Archives of Wapner, Newman, Wigrizer & Brecher's Lead Medical Situational Analyst

(Parties' names withheld due to confidentiality and privacy concerns)

Wapner, Newman, Wigrizer & Brecher Litigation Resets The Local Philadelphia Maternal-Fetal Medicine And Neonatology Standards Of Care To Conform With The International Standard Of Care For Reasonable Interventions To Prevent Harm To Babies Born To Mothers With Known Isoimmunization (Alloimmunization) To Paternally Derived Fetal Platelet Antigens

As another consequence of the litigation, the firm has recovered a large amount of money for a little girl with a shriveled, useless arm, an injury which was avoidable but for medical negligence.

Based largely on the research efforts of WNW&B's lead medical situational analyst, attorney John King, litigation has forced leading doctors caring for complicated pregnancies and sick newborns at a major Philadelphia maternity hospital to re-evaluate their practices concerning the care they deliver in cases of both potential and actual neonatal isoimmune thrombocytopenia (a/k/a neonatal alloimmune thrombocytopenia), known as NIIT (a/k/a NAIT).

NAIT is a rare, transient disease of fetuses and newborns, which can cause devastating bleeding during the late pregnancy, birth, and/or immediate postpartum neonatal period, resulting in death or permanent neurological damage to the baby. Very importantly, subsequent children born to the mother of an affected baby are at very high risk of also having the disease, often in a much more severe form than children from earlier pregnancies. Consequently, the subsequent pregnancies of such women must be closely managed to try to minimize the risk to the baby.

Understanding the pathophysiology of NAIT is the key to successful management. Unfortunately, depositions taken in this case demonstrated that many residents intimately involved in this client's prenatal care and delivery had no accurate understanding of the pathophysiology of this condition, and hence had no appreciation of the potential consequences of their flawed plan of care, nor of the flaws themselves.

Conceptually, NAIT is roughly analogous to Rh disease of the newborn. Basically, NAIT results from a logically predictable interplay between the mother's genetic constitution, the mother's immune system, the mother's previous exposure to blood or to pregnancy, and certain glycoproteins on the platelets in the baby's blood which were inherited from the baby's biological father. Platelets are small cell fragments in a person's blood which are essential to preventing bleeding by plugging up small holes or tears in the blood vessels, forming the initial clot upon which a permanent, stronger clot forms from other blood proteins. Without sufficient platelets in the blood (a condition known as thrombocytopenia), a person bleeds very easily and profusely from even very minor trauma, or even from no trauma at all. The most severe consequence of such bleeding, short of death, is permanent brain injury from bleeding into the brain. In this disease (NAIT), it is the baby, not the mother, who develops thrombocytopenia.

In NAIT, the mother's immune system has formed certain antibodies which attack antigens (certain inherited glycoproteins) located on the baby's platelets, and which cause those platelets to be destroyed. These antibodies can cross the placenta and enter the baby's bloodstream while the baby is in the mother's uterus (womb). Once in the baby's bloodstream, the antibodies cause destruction of the baby's platelets, resulting in thrombocytopenia, which can potentially result in severe bleeding. In order to prevent bleeding, the baby's platelets must be replaced by platelets which will not be destroyed by the mother's antibodies, until after the baby has been delivered and sufficient time has passed that the maternal antibodies will have been cleared from the baby's system.

Most mothers do not make antibodies which destroy their own baby's platelets. That is because, by far, most mothers themselves possess the alleles ("genes") which code for making the antigens found on their baby's platelets, hence the mother's own platelets have those same antigens, and so the mother's immune system "learned" in her own infancy not to make those specific antibodies because they would destroy the mother's own platelets. Most people possess at least one copy of the allele (gene) which codes for these platelet antigens. However, a very few people lack any copy of the allele which makes these platelet antigens, and hence do not have those antigens on their own platelets. Those few people, when they happen to be fertile females, are potential mothers of babies with NAIT, because they are capable of producing antibodies against those very common platelet antigens.

In addition to lacking the alleles (genes) to produce the platelet antigens, a woman must first be "sensitized" to those antigens before her baby will be at significant risk of developing NAIT. This means that the woman's immune system must have "seen" (been exposed to) those antigens, which normally will happen when she delivers a child or aborts or miscarries a fetus which has the antigens on its own platelets, or when she receives a transfusion of blood containing platelets with those antigens, or when she receives a mixed platelet concentrate transfusion. Virtually all mixed platelet concentrate contains the antigens. Most transfused blood contains the antigens, except for blood from donors specifically platelet typed as negative for those antigens, a test which is not commonly done for most transfusions. Most pregnancies, fathered by men who have the platelet antigen allele (the vast majority of men), involve fetuses who also have the allele and who therefore have platelets with the antigen on them.

In the case handled by WNW&B, the plaintiff baby girl was not treated appropriately even though the doctors knew that her mother had previously given birth to a child with a case of NAIT. While the prior child had escaped with a relatively minor injury (a partially paralyzed upper lip) from a small bleed, his subsequently born sister suffered a massive brain bleed beginning about 10 hours after delivery, resulting in extensive damage affecting many of her neurological functions, most prominently including a total and permanent loss of function of one arm and hand, which eventually shriveled from disuse. Those 10 hours provided a substantial and adequate "window" of time after the delivery which should have been used to transfuse the infant with appropriately typed platelets which would not be destroyed and which would have forestalled the bleed and the neurological injury. Those specific platelets were not provided, and in fact plans to make them available had never been made.

The initial contact with WNW&B, via an evening phone call from the children's mother, was fortunately received by Mr. King. The mother, having previously been told by other law firms after investigation that her younger daughter "had no case," was calling concerning her older son, whom she thought had suffered a forceps injury at birth. Through probing questioning and probability-based situational analysis, coupled with a basic understanding of medical physiology, immunology and genetics, Mr. King elicited sufficient information to determine that the daughter was injured, had suffered a much more serious injury, and that her injury was apparently due to medical negligence, a failure to provide preventive care which was clearly logically necessary. Proving that turned out to be a bit more complicated.

After the birth of the older son, the mother had eventually been determined through antibody testing to have significant circulating antibody titers against the common platelet antigen, and the boy was retrospectively diagnosed as having had NAIT once it was recalled that the mother had suffered an earlier miscarriage (at which time she had presumably been sensitized). The mother's own platelet typing eventually was, unsurprisingly, determined to be negative for the platelet antigen. She was again placed in high-risk care for her subsequent pregnancy (which she had been in previously due to the earlier miscarriage), but the ball was dropped.

Mr. King determined, through focused and directed questioning, that the mother had four full siblings (sisters and brothers who had the same mother and the same father). After doing some literature research which suggested that the platelet antigen inheritance was a single-gene multiple-allele autosomal dominant system, it appeared clear that each of the maternal full siblings had at least a 25% chance of having platelets free of the antigen, with a very high likelihood that at least one of them would have been free of the antigen and so could have served as a platelet donor for the affected child on demand. (The child needed transfusion of platelets which would not be destroyed by the antibodies from the mother, and therefore needed platelets, like the mother's, which did not have the antigen. While the mother's washed platelets could theoretically have been used, it would have been logistically and technically difficult to have her own platelets available to the child when needed, without putting the mother herself at risk.)

WNW&B had the mother's siblings tested (as should have been done earlier by the maternal-fetal medicine doctors, but was not) and determined that there were indeed suitable platelet donors among them. This short-circuited defense arguments that suitable platelets could not have been obtained to timely treat the child with platelet transfusion at the moment of birth.

Although it was logically obvious that adequate obstetric care of a patient with a known prior child affected by NAIT should, at the least, include planning to have suitable antigen-negative platelets available at the time of delivery to immediately transfuse into the newborn, finding an obstetric expert who had even considered that treatment possibility turned out, initially, to be problematic. Most maternal-fetal medicine specialists, being obstetricians, focused their attention on high-tech experimental prenatal care involving highly risky attempts to transfuse such platelets into the fetus' umbilical cord vessels while the baby was still in utero. Such high-tech care is (or was at the time) considered to be too experimental and risky to be considered standard care for this condition, and it is not medically negligent to fail to give risky experimental treatments. Once the baby was delivered, the baby's care would be assumed by the neonatologists, who are pediatricians, and would be out of the hands of the obstetricians.

Unfortunately, the transitional moment of birth can (but should not) place a newborn into the hands of a doctor with no prior knowledge of the child's medical history and no opportunity to have prepared for the child's predictable problems.

Although in theory there should be extensive communication between the maternal-fetal medicine obstetricians and the neonatologist pediatricians concerning pregnancies with a potential of producing an infant requiring immediate specialized care, in practice such communication is often inadequate. In this case, joint planning of comprehensive care was minimal if it existed at all. There was no coordination between maternal-fetal medicine and neonatology to procure compatible platelets in anticipation of the birth. At best, the neonatologists were informed that there was a potential NAIT baby somewhere in the "pipeline" of upcoming future deliveries, and did not pursue the details that they should have pursued in order to insure their own preparedness.

Refusing to believe that no one had ever considered this situation, Mr. King spent several days searching the medical literature. Eventually he found a published, peer reviewed medical journal article which was exactly on point. A prominent international obstetric specialist who had done extensive research concerning NAIT had published an article specifically exhorting doctors caring for patients with this condition to prepare well ahead of delivery for the immediate treatment of the newborn with compatible platelets. The article was virtually a recipe for the proper management of this condition without relying on experimental (and de facto unavailable) high-tech intrauterine transfusion. The cornerstone of management was insuring the immediate availability of compatible platelets at the time of birth.

WNW&B contacted the author of the article, who at the time of publication had been in Canada but who had relocated to Australia in the interim. Providing him detailed summaries and analysis of the relevant facts of the case, Mr. King convinced the author to provide an expert report which was crucial to the successful resolution of the case and instrumental in convincing the Philadelphia defendants that their approach to this disease needed to be re-evaluated.

One of the defendant attending doctors had, at his deposition, declared that his own opinion defined the standard of care, as he was the leading authority in the area on maternal-fetal medicine. Upon resolution of the case, his opinion had been shown to be less than reasonable in the circumstances of management of this disease. Hopefully, his future patients will be the true beneficiaries of this litigation.